1. Introduction
This invention relates to an improved ozonation system for treatment of cooling tower water typically utilized in conjunction with the operation of large-scale cooling and air-conditioning equipment and, more particularly, pertains to significant advances in the efficient operation of an ozone generation system keeping it at optimal operation condition, protecting the ozonation system, and informing others of problems within the system.
2. Prior Art
Ozone has been used in the treatment of drinking water for more than 100 years. While there is much literature on the subject, the more modern work done with ozone is summarized in an article by Maurice Ogden of Water Treatment Corp. appearing in the June, 1970 issue of "Industrial Water Engineering". This article discusses the use of ozone to treat water. It mentions an ozone treatment plant built and put into operation in 1949 by the Philadelphia Water Works, and reviews advances in acid-resistant materials for air conditioning systems and breakthroughs in electrical circuitry design allowing for the development of a more efficient ozone generating unit.
U.S. Pat. No. 4,172,789, issued Oct. 30, 1979, discloses the type of structure described in the above article, namely a water tower with means to generate ozone, mix the water tower water with the generated ozone, and then return the ozone enriched water to the tower.
H. Banks Edwards discusses the use of ozone as "an alternate method of treating cooling tower water" in the Journal of the Cooling Tower Institute, Vol. 8, No. 2, 1987, page 10. Edwards illustrates a more sophisticated cooling tower than that of the '786 patent. The article discloses dividing the water coming from the tower so a sample portion goes back into the tower while the remaining portion is ozone enriched.
A paper was presented on "Ozone Treatment of Cooling Water: Results of a Full-Scale Performance Evaluation" at the 1989 Cooling Tower Institute Annual Meeting by G. Darell Coppenger, Benjamin R. Crocker, and David E. Wheeler. The paper also verified the many benefits of oxygenation. It shows (FIG. 3, page 21) the use of a personal computer to operate the system and means to monitor the quality of the water and the voltage potential across an ozone sensing probe.
Further developments are illustrated in the catalog of Ozonair International Corp. of South San Francisco, Calif., which illustrates specially designed sensor electrodes with solid state and transistorized circuitry. Another sophisticated example is the ozone self-contained injection system of Prosys of Chelmsford, Mass.
All of these systems, while feasible and performing in the field, do not develop a sufficient volume of ozone for the number of electrodes. They do not provide true commercial benefits.